Question

please solve question no. 18 please do it fast

Answer 1

Let, x = audio cassettey = video cassetteaccording to the given data,
( a ). 7x + 3y = 1110
( b ). 5x + 4y = 1350
multiply (a) by 4 and (b) by 3 which gives you the following,
( c ). 28x + 12y = 4440
( d ). 15x + 12y = 4050
now subtract (d) from (c),
13x = 390x = 390/13x = 30 rs
substitute the value of x in (a),7(30) + 3y = 1110210 + 3y = 11103y = 1110 - 210y = 900/3y = 300 rs
cost of audio cassette = 30 rscost of video cassette = 300 rs
here you go bud

Answer 2

Heya !!!

Here is your answer.

Given :
7 audio casettes and 3 video cassettes cost Rs. 1110

While

5 audio casettes and 4 video casettes cost Rs 1350.

Let the cost of Audio casettes be x and that of video cassettes be y.

Therefore,
7x + 3y = 1110 (i)
5x + 4y = 1350. (ii)

Multiply (i) by 4 and (ii) by 3, we get....
28x + 12y = 4440 (iii)
15x + 12y = 4050 (iv)

Now, Subtract (iv) from (iii),

28x + 12y = 4440
15x + 12y = 4050
---------------------------
13x = 390

x = 30
Putting x = 30 in (i), we get.....
7 × 30 + 3y = 1110
210 + 3y = 1110
3y = 900
y = 300

Hence, the cost of an audio casette is Rs. 30 and that of video casette is Rs 300


Hope You Got It